2357P vs XXI
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
2357P
A simple number-based game where players decompose and compose numbers using prime bases 2, 3, 5, and 7. Aim to achieve higher scores and compete on the Game Center leaderboard.
- Number decomposition
- Number composition
- Prime number bases (2, 3, 5, 7)
- Score-based gameplay
- Game Center leaderboard integration
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2357P is a simple game about number. 2, 3, 5 and 7 can compose many numbers, decompose numbers with these base numbers and go for higher score! 2 * 3 = 6 2 * 3 * 5 = 30 2 * 3 * 5 * 7 = 210 2 * 2 * 3 * 5 = 60 2 * 2 * 3 * 5 * 7 = 420 P = any prime number that can't be decomposed Try to break the record and see who's on the Game Center leaderboard!
XXI
This puzzle game challenges you to arrange numbered gems on a board so that each row and column sums to 21. Progress through 200 levels of increasing difficulty, utilizing a special gem that can be 1 or 11. Compete with others via leaderboards and share your achievements.
- 200 unique puzzles
- Special gem mechanics
- Game Center achievements
- Leaderboard competition
- Beautiful graphics and sound
- Universal app support
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XXI puzzles require a sum of 21 in every row and column. Move the gems around on the board until a solution is found. All gems have a unique numerical value, but watch out for the special gem that can be either a 1 or 11. Puzzles get harder as you progress your way through all 200 levels. Can you become a XXI champion? FEATURES - 200 Unique & Challenging Puzzles - Game Center Achievements (V, X, L, C, CC) - Game Center Leaderboard for Highest Level - Beautiful Music, Sounds, and Retina Graphics - Universal App looks Great on iPhone and iPad - Share Solution Photos with Friends Thanks for playing XXI by TMSOFT and good luck! Website: https://www.tmsoft.com/xxi/
Screenshots
Verdict
The clearest difference is rating: XXI at 4.9 against 2357P's 3.0. XXI also leads on ratings volume (15 vs 2) and iOS requirement (11.0 vs 15.0). 2357P's advantage is ads (none vs shown) and monetization model (free vs ad-supported). On price, update cadence, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
XXI holds the better App Store score, 4.9 against 3.0. That said, the two scores are not equally well evidenced: XXI has 15 ratings behind it against 2, so its average is the more settled of the two.
2357P ships an update every 15 months, XXI every 17 months. The most recent releases landed on June 1, 2026 and August 13, 2026 respectively.
| Parameter | 2357P | XXI |
|---|---|---|
| Price | Free | Free |
| Rating | 3.0 (2 ratings) | 4.9 (15 ratings) — better |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 2 | 15 — better |
| Update frequency | Every 15 months — better | Every 17 months |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 15.0 | 11.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 27 MB |
| Age rating | 4+ | 4+ |
| Developer | Yuantong Lu | TMSOFT |
Customer experience
2357P
XXI
In-app purchases
2357P
No in-app purchases
XXI
No in-app purchases
